1. Field
Various embodiments discussed herein relate to a storage system, a storage control method, and a computer-readable recording medium that stores a storage control program for controlling a storage.
2. Description of the Related Art
In the past, a storage system including business servers sharing a group of storage devices as a virtual area was disclosed in Japanese Laid-open Patent Publication No. 2005-004681.
FIG. 12 shows a system configuration of a storage system. A storage system 900 includes a data center 901 and a group of business systems 902. In the storage system 900, the data center 901 and the group of business systems 902 are communicably connected to each other via a network 903 including a local area network (LAN), a wide area network (WAN), the Internet, and so forth.
The data center 901 is configured to provide storage service to the group of business systems 902. The storage service denotes computer processing performed to provide data reading and/or data writing to each of the business systems 902. The data center 901 includes a management node MP, a control node CP, and a plurality of storage devices ST. The management node MP is a computer configured to manage a business server S installed at the service provide destination. The control node CP is a computer configured to collectively manage the disk areas of all of physical disks Da.
The storage device ST includes a disk node DP and the physical disk Da. The disk node DP is a computer configured to read data from the physical disk Da and/or write data onto the physical disk Da under the control of the control node CP. The physical disk Da includes a hard disk, a nonvolatile memory, and a magnetic tape.
Disk areas are generated on the physical disk Da in the unit slice. The slice is allocated to each of the business servers S through the management node MP. A slice allocated to a certain business server S extends over a plurality of the physical disks Da. To each of the business servers S, however, the physical disks Da are recognized as a single physical disk. Therefore, the disk areas of all of the physical disks Da are referred to as a virtual area V (or a virtual disk).
The business system 902 is configured to provide various tasks (for example, a Web service, a search service, a storage service, and so forth) and includes the business server S and a physical disk Db specifically provided for the business server S. The business server S is a computer accepting a storage allocation service presented by the data center 901. Each of the business servers S may read data stored in the virtual area V and/or write data onto the virtual area V. In actuality, each of the business servers S accesses a slice generated in the physical disk Da of a disk node DP, the slice being allocated to the business server S, and reads and/or writes data from and/or onto the slice.
The physical disk Db of the business server S is used by the business server S. If the physical disk Db of each of the business servers S includes an available area, it means that a plurality of the available areas is dispersed. In that case, the storage system 900 is operating inefficiently.